It is common in construction set toys to provide a circularly cross-sectioned element of one type or another which is capable of being rotatably attached to other elements in the set to provide a wheel. With such wheels it is also common to provide a flexible, annular ring which fits snugly over the wheel to serve as a tire, thereby enhancing the aesthetic appearance of the toy.
However, such tires commonly are in the form of a rubber "O" ring which fits over the rim of the wheel into a groove which is formed in the wheel for the purpose of carrying the tire. While tires of this type perform satisfactorily when new, after repeated removal and replacement they typically become stretched to the point where they no longer adhere to the rim. When this occurs they no longer function in a satisfactory manner. In addition, with tires of this type it is not economically feasible to place a tread design on the outer face of the tire, thereby making it a less than an ideal tire replica and not providing any traction capability.
While slip-on tires having lugs are known in the prior art, these primarily are in the form of a tractor tread comprising a thin belt which fits over a spaced-apart set of wheels. Accordingly, this type of tire also relies on elasticity of the tire to effectuate joinder between the tire and the wheel, and, when this type of tire becomes stretched with use it also slips relative to the wheel and eventually reaches a point where it will no longer function well as a tire either.
Furthermore, all of the prior art tires of this type require a specially configured wheel which is arranged for receiving the tire and for rotatable joinder to the rest of the elements of the construction set. Therefore, since the wheels must be produced separately from the other elements of the construction set and are not capable of serving any other purpose for the construction set, their cost is quite high and they typically are only provided with more expensive models of the set.
What is needed, therefore, is a tire which can be readily attached to a common pre-existing element of a construction toy set, which positively adheres mechanically to the construction set element and yet is easily removable therefrom, and which in addition has a lugged tread on its outer surface.
The present invention achieves these results by providing a tire for a construction set of the type having hollow, generally-spheroidal joint elements which include planar facets located around its periphery with joint openings located in each of the facets. The facets in the joint element are arranged so that a portion of them circumscribes the joint element in a particularly defined pattern around a diametric axis of the joint element. Also, the joint openings which lie along the axis, on both ends of the joint element, are circular, while the joint openings in the remainder of the facets are elongate. Therefore, a strut having a clip fastener which is shaped corresponding to the shape of the elongate joint openings will be fixed when attached to these openings and yet will be rotatable when attached to the round joint opening. As a result, by connecting one end of a short strut to a round joint opening in one joint element, and the other of the strut end to an elongate joint opening in another joint element, the former joint element will be rotatable with respect to the latter element. The rotatable joint element then serves as a wheel upon which the tire of the present invention is attached.
The tire comprises an annular rim having a width which is slightly greater than the width of the facets on the joint element and has a plurality of engaging surfaces on its inner face which mate with the facets on the joint element, thereby preventing rotation of the tire relative to the joint element once it is in place. In addition, elongate protrusions having the general shape of the elongate joint openings, extend inwardly from each of the engaging surfaces to seat within the joint openings when the tire is in place on the joint element, thereby further securing the tire to the joint element.
Located at spaced intervals around the outer periphery of the tire are upstanding lugs which are rectangular in cross section and which are spaced apart by a distance which is slightly greater than their width. Therefore, in addition to simulating tire tread the lugs serve as gear teeth which intermesh with the lugs on an adjacent tire.
Accordingly, it is a principal object of the present invention to provide a tire for attachment to a joint element of the class described which is firmly securable to the joint element and yet is easily removable.
It is a further object of the present invention to provide such a tire which is aesthetically similar to an actual lugged tire.
The foregoing objectives, features and advantages of the present invention will be more readily understood upon consideration of the following detailed description of the invention taken in conjunction with the accompanying drawings.